The present invention relates to controlling the movement of a barrier with respect to an opening in a wall.
Powered barrier operators are known and have been used to automatically move barriers such as garage doors. One type of barrier operator, referred to herein as a jack shaft operator, includes a jack shaft mounted above the door opening and including one or more flexible cables which are attached to the vertically moving door near the bottom thereof.
In known jack shaft operator systems, tracks to guide door movement are mounted to the carpentry frame surrounding a door opening in a wall and the jack shaft is mounted to the support for the tracks and/or to a header above the opening. Cables are also used to connect drums or sprockets on the jack shaft to the door near its bottom. The door is moved by a motor which is attached to the wall near the jack shaft to power rotation thereof. Such coupling may include chains, belts or gears. After assembly, energizing the motor to rotate causes the door to be raised or lowered, depending on the direction of rotation.
The above structure and method may create difficulties in the assembly and use of an automated barrier movement system. The motor housing must be attached to a structural part of the wall, such as wall studs, in order to reliably resist the rotational forces created when the motor is energized. Frequently, there is no structural part where one is needed so the barrier installer must build one. Further, if the wall structure has been covered by for example, plaster or drywall, the finding of a structural part even if present may be difficult and time consuming. In other previous systems, the motor of the operator must be placed above the barrier in order to allow the system to function properly.